WASHINGTON, April 25 (Xinhua) -- Former U.S. Vice President Joe Biden formally announced his candidacy for the 2020 presidential elections in an online video on Thursday.

"The core values of this nation, our standing in the world, our very democracy, everything that has made America America is at stake," Biden said in the video posted on Facebook and Twitter.

"That's why today I'm announcing my candidacy for president of the United States," he said.

In the statement, Biden also slammed the white supremacist rally in Charlottesville, Virginia, in August 2017 and President Donald Trump's handling of the incident. The rally saw a Nazi sympathizer ram his car into a group of peaceful counter-protesters, killing one and injuring 19 others.

Trump said in response then that there were "very fine people on both sides." Biden said, "With those words, the President of the United States assigned a moral equivalence between those spreading hate and those with the courage to stand against it. And in that moment, I knew the threat to this nation was unlike any I had ever seen in my lifetime."

He said history will look back on Trump's presidency as "an aberrant moment in time."

"But if we give Donald Trump eight years in the White House, he will forever and fundamentally alter the character of this nation, who we are, and I cannot stand by and watch that happen," he noted.

Biden is expected to attend his first high-dollar fundraiser held at the Philadelphia home of Comcast executive David Cohen on Thursday evening, and to show up at a local union hall in Pittsburgh on Monday.

With strong support from older voters and African Americans and thanks to the fact that his name is well-known, Biden currently leads more than a dozen Democratic hopefuls for the party's 2020 presidential nomination, according to the Reuters/Ipsos poll released on Wednesday.

The former vice president is supported by 26 percent of likely Democratic primary voters, followed by Senator Bernie Sanders with 15 percent, the poll showed. About 40 percent of African Americans and 32 percent of those aged 55 and older said they support Biden.

No other Democratic candidate, including notable names such as Senators Kamala Harris and Elizabeth Warren, as well as former House member Beto O'Rourke and rising star Pete Buttigieg, the mayor of South Bend in the state of Indiana, garnered the support of more than 7 percent of the respondents.

Biden, born in Scranton, Pennsylvania, became an attorney in 1969 and was first elected to the U.S. Senate in 1972 as the sixth-youngest senator in U.S. history. He served as the U.S. vice president from 2009 to 2017.

During his nearly four decades in the Senate, he was a longtime member and former chair of the Foreign Relations Committee. He also served as chair of the Senate Judiciary Committee.

Biden launched a bid for the 1988 Democratic nomination and ran a second time in the 2008 cycle. He reportedly seriously considered another run for the White House in 2016, but announced in October 2015 that he would not launch a campaign following the death of his eldest son Beau.